The disclosure generally relates to communication devices and, more particularly, to communication devices with intelligent frequency hopping channel selection capability.
Wireless communications have brought people the convenience in every aspect of life and therefore wireless communication devices are getting more and more popular. Some wireless communication devices constantly occupy a specific frequency band for performing communications so that the communications of other devices in the same frequency band are affected. To avoid or reduce the interference in those specific frequency bands, some communication systems adopt an adaptive frequency hopping (AFH) technique. For example, the Bluetooth standard adopts the AFH technique for performing the transmission of speech, data, and control signals.
The communication devices adopting the AFH technique must have the capability to generate the channel map for performing adaptive frequency hopping communication. The channel map keeps a record of the locations of the good channels and the bad channels in a specific frequency band. The good channels are the channels with which the communication devices usually try to perform frequency hopping communications so as to achieve a better communication performance. On the other hand, the bad channels are the channels without which the communication devices usually try to perform frequency hopping communications so as not to degrade the communication performance. Thus, the communication devices must know the locations of the good channels and the bad channels, and record them in the channel map.
An interference signal may appear, disappear, or vary its signal strength when a communication device is turned on, turned off, or moved in the neighborhood. Thus, a good channel in the channel map may become a bad channel and a bad channel may also become a good channel at different periods of time. The communication devices adopting the AFH technique must be aware of the communication conditions of the channels and keep recording in the channel map as many good channels as possible to maintain the communication performance at an acceptable level. Therefore, the communication devices must perform signal transmission tests to evaluate the communication conditions of the channels, and keep updating the channel map accordingly.
When performing the signal transmission tests to evaluate the communication conditions of the channels, the communication devices usually performs frequency hopping communications with several good channels in company with one or more channels under test. Even if one of the channels under test is a bad channel, the communication performance may be still degraded. Thus, if the communication device does not perform the signal transmission tests and update the channel map with a suitable mechanism, the communication performance may be severely degraded and the communication may not even be sustainable.